Beautiful Number
http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=2829
Mike is very lucky, as he has two beautiful numbers, 3 and 5. But he is so greedy that he wants infinite beautiful numbers. So he declares that any positive number which is dividable by 3 or 5 is beautiful number. Given you an integer N (1 <= N <= 100000), could you please tell mike the Nth beautiful number?
Input
The input consists of one or more test cases. For each test case, there is a single line containing an integer N.
Output
For each test case in the input, output the result on a line by itself.
Sample Input
1
2
3
4
Sample Output
3
5
6
9
题目思路,刚开始我以为只有能被3或5整除的数为beautiful number,英语翻译过来后是只要能被3或5整除的数为beautiful number,那么就简单了,
预处理一下,map映射随便做。注意,最大是第100000个数,而不是beautiful number最大是100000。
#include <iostream> #include <cstdio> #include <cstring> #include <queue> #include <cmath> #include <vector> #include <set> #include <map> #include <algorithm> using namespace std; typedef long long ll; map<ll,ll>m; void getbeautifulnumber() { int p=1; for(int i=1; ;i++) { if(p>100000) break; if(i%3==0 || i%5==0) m[p++]=i; } } int main() { int n; getbeautifulnumber(); while(scanf("%d",&n)!=EOF) { printf("%d\n",m[n]); } return 0; }